Question .blend - Imported objects seems to all group together.

I have a .blend file with 4 objects under their own collection as shown here:


When directly imported into Unity the four objects appear in their prefab preview like this, individually seperated. ("Blocks" is the .blend file)


However when trying to drag one of the generated prefabs into the scene view it look like this:

No matter which one I drag into the scene view all 4 objects appear together.

For import context this is the model settings on the .blend file. (Rig and Animation are both to not import - Materials is untouched.)


So my question is: "How do I make each preview only drag their previewed object".
It looks fine in the preview, exactly how you would expect it to behave but when dragging it into the scene view they all follow.
Does anyone know why and/or how to fix it?

Thank you in advance